Newer designs and manufacturing techniques have driven electronic components to small dimensions and miniaturized many communication devices and systems. Unfortunately, antennas have not been reduced in size at a comparative level and often are one of the larger components used in a smaller communications device. For example, the FCC now allows Ultra Wide-Band (UWB) communication devices to operate at low power in an unlicensed spectrum from 3.1 to 10.6 GHz. One application of this spectrum is the networking of Unattended Ground Sensors (UGS) that utilize UWB communication devices. For such applications there is a need for antennas with broad bandwidth, relatively small volume, and reasonable manufacturing cost.
In current practice, communications devices are used with many different types of dipoles, biconical dipoles, conical monopoles and discone antennas. These antennas, however, are sometimes large and include impractical shapes for a specific application.
Conical antennas, which include a single inverted cone over a ground plane, and biconical antennas, which include a pair of cones oriented with their apexes pointing toward each other, are used as broadband antennas for various applications, for example, direction finding. A biconical antenna includes a top inverted cone and a bottom cone. An electronic coupler provides a connection to a feed circuit that provides the electrical signal that feeds the antenna. The antenna is symmetric about the cone axis and each of the cones is a full cone (spanning 360°). Similarly, a single cone antenna includes a single antenna cone (also spanning 360°) which is symmetric about the cone axis. A single antenna cone is connected to an electronic coupler that provides a connection to a feed circuit that provides the electrical signal to the antenna. The single cone antenna is located over a ground plane.
For example, U.S. Pat. No. 6,198,454 to Sharp et al. is directed to a broadband partial fan cone antenna. The antenna includes a radiator having a partial cone shape.
However, none of these approaches focuses on providing a small low-cost broadband antenna.